نتایج جستجو برای: carbonaceous phosphorites

تعداد نتایج: 4406  

2010
Chandra Wickramasinghe

It is nearly 30 years since the first decisive evidence of microbial morphologies in carbonaceous chondrites was discovered and reported by Hans Dieter Pflug. In addition to morphology, other data, notably laser mass spectroscopy, served to confirm the identification of such structures as putative bacterial fossils. Recent examinations of cometary dust collected in the stratosphere and further ...

1998

An atmospheric general circulation model is coupled to an atmospheric chemistry model to calculate the radiative forcing by anthropogenic sulfate and carbonaceous aerosols. The latter aerosols result from biomass burning as well as fossil fuel burning. The black carbon associated with carbonaceous aerosols is absorbant and can decrease the amount of reflected radiation at the top-of-the-atmosph...

2005
F. Yang K. He B. Ye X. Chen L. Cha S. H. Cadle

Weekly PM2.5 samples were collected for one year (1999–2000) in Beijing and Shanghai and the carbonaceous species analyzed to investigate and compare their time series patterns and possible sources in the two biggest cities of China. Weekly carbonaceous concentrations varied in wide ranges with 8.6–59μg m−3 for OC and 1.5– 25.4μg m−3 for EC in Beijing, and with 5.1–38.4μg m−3 for OC and 2.3–13....

Journal: :The Analyst 2013
Zheng Guo Myeong-Lok Seol Moon-Seok Kim Jae-Hyuk Ahn Yang-Kyu Choi Jin-Huai Liu Xing-Jiu Huang

A highly sensitive and selective electrochemical sensor of dopamine (DA) has been developed by employing carboxylated carbonaceous spheres to modify glassy carbon electrodes (GCEs). Scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy were used to characterize as-prepared carbonaceous spheres. The results show that the diameter of carboxylated carbonaceous sphe...

2014
Masayuki Uesugi Hiroshi Naraoka Motoo Ito Hikaru Yabuta Fumio Kitajima Yoshinori Takano Hajime Mita Ichiro Ohnishi Yoko Kebukawa Toru Yada Yuzuru Karouji Yukihiro Ishibashi Takaaki Okada Masanao Abe

Preliminary results of the analyses of five carbonaceous materials (particle size of approximately 50 μm) from the Hayabusa spacecraft sample catcher, including their texture, chemistry, and chemical/isotopic compositions, are summarized. The carbonaceous particles underwent sequential analysis using a series of microanalytical instruments located at several research institutes and universities...

2013
W. - C. Hsieh W. D. Collins Y. Liu J. C. H. Chiang C. - L. Shie K. Caldeira L. Cao

This study used the Community Atmospheric Model 3.5 (CAM3.5) to investigate the effects of carbonaceous aerosols on climate. The simulations include control runs with 3 times the mass of carbonaceous aerosols as compared to the model’s default carbonaceous aerosol mass, as well as no-carbon runs in which carbonaceous aerosols were removed. The slab ocean model (SOM) and the fixed sea surface te...

2010
S. S. Dimov

An increasing number of low-grade gold ore deposits are characterized by the presence of gold as solid solution into the mineral matrix of sulphide minerals which is not directly amenable to gold cyanidation. In order to liberate this submicroscopic gold the ore has to be oxidized before being subjected to gold cyanidation and exctraction. This is mainly done by autoclave pressure oxidation (AC...

2012
CHONDRITE PARENT

Oxygen isotope ratios of large cosmic spherules: Carbonaceous and ordinary chondrite parent bodies Conference Item How to cite: Suavet, C.; Alexandre, A.; Franchi, I. A.; Gattacceca, J.; Sonzoghi, C.; Greenwood, R. C.; Folco, L. and Rochette, P. (2009). Oxygen isotope ratios of large cosmic spherules: Carbonaceous and ordinary chondrite parent bodies. In: 40th Lunar and Planetary Science Confer...

2016
L. Baker I. A. Franchi P. A. Bland

The Open University's repository of research publications and other research outputs Insight into the evolution of the Tagish Lake carbonaceous chondrite by analysis of the oxygen isotopic composition of extracted water and Mssbauer spectroscopy Conference Item (2001). Insight into the evolution of the Tagish Lake carbonaceous chondrite by analysis of the oxygen isotopic composition of extracte...

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